Burring machine



April 13, 1943. l R. s. DRUMMoND BURRING MACHINE Original Filed Jan. 10, 1958 .3 Sheets-Sheet l .D S N Y E m M mgm ,movA T BY y www.

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April 13, 1943.V

R. s. DRUMMOND BURRING MACHINE orginal Filed Jan. 1o, 193s 3 Sheets-Sheet 2 INVENTOR BY www,

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Patented Apr. 13, 1943 BURRING MAOHINE Robert S. Drummond, Detroit, Mich., assigner to National Broach & Machine' Company, Detroit, Mich., a corporation of Michigan original application January 1c, 193s, serialV No. 184,283. Divided and this application August 14,1939, serial. No. 290,00?,l

4 claims. (cl. :io- 1.4)

The present invention relates to aburring machine and more particularly to an automatic machine for removing the sharp edges from the teeth of gears. This application is a division of my co-pending application, Serial No. 184,283, Burring machine, filed January l0, 1938.

` It is an object of the present invention to provide a machine of the type described in which the work spindle is automatically indexed in operation.

It is a further object of the present inven tion to provide a machine in which the Work spindle is axially translated to and from working position and is automatically indexed by such translation. j

It is a further object of the present invention to provide a novel indexing mechanism which serves also as a guide and locking means for the work spindle in working position.

Other objects of the invention will be apparent as the description proceeds, and when taken in conjunction with the accompanying drawings wherein:

Figure l is an elevation of the machine with parts broken away for clearness;

Figure 2 is a plan view of the machine;

Figure 3 is a vertical section through the air cylinder;

Figure 4 is a iront elevation of the index rack bracket;

Figure 5 is a side elevation of the part shown in Figure 4;

Figure 6 is a plan of the part shown in Figure 4;

Figure '7 is a front elevation of the index gear; and

vFigure 8 is a side elevation of the index gear sectioned on the line 8 8 of Figure 7.

The machine which forms the subject matter of the present invention comprises essentially a work spindle, upon which is mounted a work piece, in the present instance, a gear. It is desired to perform operations on spaced parts of the work piece, in the example shown, upon the gear teeth.

For this purpose one or more tools, in th present example, two rotary cutters, are provided in adjustable but relatively xed position on the machine. These cutters may be separately driven or driven from a single source of power, or, if desired, driven from the motor which controls the work.

The work spindle, which may be a stub shaft presenting a free end, or a shaft having a headstock and resilient tailstock, is slidably mounted in a suitable bushing.- Motor means reciprocate the shaftl axially, to and from a definitely located working or cutting position, so as to permit the tools to take predetermined cuts on the work piece.

vAutomatic indexing means are provided, so that as said spindle is reciprocated, it is intermittently rotated by predetermined amounts, and is then accurately guided without rotation into engagement with the tool or tools. In the example illustrated, this indexing mechanism takes the form of an index gear reciproeated between two short rack sections, the teeth of thev rack being staggered and the teeth of both racks and index gear being beveled.

With the foregoing general description in mind, reference is now made to the gures.

The machine shown as a whole in Figures 1 and 2 comprises a frame III upon which is mounted a headstock housing II, adjustably mounted in ways indicated at I2, A Work spindle generally indicated at is reciprocab-ly and rotatably mounted in the housing.

A motor I5 is carried on a platform I6 within the frame of the machine and drives a shaft i1 which connects through a coupling I8 to a worm shown at I8 within a housing I9. The Worm drives a gear which connects to crank shaft |98. A link 2l) is connected` to crank arm I9b, and at its other end is connected by pin 23 to lever 2I. Lever 2I is .pivoted substantially centrally on pin 22 which is trunnioned in the frame. The upper end of lever 2| presents a. yoke 26 and inwardly projecting pins 26a which n engage in an annular groove 24 in spindle 25.

It is evident that'motor I5 causes reciprocation of spindle 25, and additionally that spindle 25 is advanced and retracted from a definite Working position.

Carriages are keyed to the frame I IJ, as at 6I, for longitudinal adjustment. A depending lug 62 is provided on each carriage, and is in screw threaded engagement for adjustment of the carriages with a threaded rod 63 provided with a turning head 64. v

Plates 65 are mounted in vertical ways on carriages 6D and are vertically adjustable by means of lugs and threaded rods, similar to those employed for horizontal adjustment of carriages 60. The turning head 66 of one such threaded rod is shown in Figure 2.

The plates 65 have spindle housings 51 there on in which are journaled tool spindles 68. These spindles are adapted to be driven from separate motors (not shown) also carried by pin '|2 provided with a flat projection |3 forv interdental 'engagement with the work gear. A shoulder 14 is provided on pin 12, against which bears spring '|5, biasing the pin in a direction to clear the work gear. Set screw 'I6 is adapted to lock pin '|2 in forward position. By proper the rm meshing engagement between the teeth, spindle 25 is accurately held against rotation as it is moved so that work W engages the tools.

As best seen in Figure 3, air cylinder 33 includes a piston rod 43 which is threaded to shaft 4| as at 42. Air passages 46 and 4'| lead to opposite sides of the piston and connect to nipples 45, only one of which appears in Figure 3. Cylinder 33 is rotatably secured to sleeve 43 as by bearings 48a. This permits rotation of the cylinder in uni- Y son with rotation of shaft 25, without rotating sleeve 48 carrying the nipples 45 which are connected to a controlled supply of fluid pressure.

Cylinder 33 is supported for rotation and recipro'cation on a laterally extending arm 30, a

. .bushing 32 being provided in enlarged apertured initial adjustment of locating pin 72, subse- Y quent loading of the gear entails only slipping the gear in place, engaging projection '|2 in a tooth space, and operating the pressure cylinder 33 tolockthe gear in place. i Y

The spindle generally indicated at 25 is slidably and rotatably mounted in housing and is also provided with a central bore 21 in which is slidably mounted shaft 4|. A short sleeve 5D, also centrally bored, is secured to one end of spindle 25 and receives a portion of shaft 4| and a shaft 53, secured to shaft 4|. Sleeve 50 is reduced in diameter as at to receive a work piece W, and to provide a shoulder 52. l. Short shaft 53 is provided with an annular projection 54. A C-washer 55 is provided, and as will be evident, when shafts 4I and 53 are moved to the right (Figure 1) the work W is securely locked in position thereby.

The opposite end -of spindle -is reduced to receive index gear 34l and locking sleeve 35 is threaded onto spindle 25 beyond the reduced portion to clampingly engage gear 34. Locking sleeve also threadedly engages air cylinder 33, and rigidly secures the cylinder and spindle 25 together.

Secured to the frame |0 on a projection 38 is an index rack bracket 36. This bracket is adjustable in vertical ways 3'| in the projection,

Vand at its upper end (see Figures 4 6) has an offset portion 86 which carries teeth 39 and 40. A slot 85 is provided in the shank of the bracket to permit vertical adjustment and clamping in adjusted position.

Rack teeth 39, as shown, are three in number. Teeth 40, two in number, are staggered with relation to teeth 39, so that a tooth is opposite each tooth space between teeth 39. Teeth 39 are beveled on their inboard edge as at 90, and teeth 4|!v are beveled on the edge confronting teeth 39 as at 9|. Teeth 40 are spaced from teeth39 by a distance just slightly less than the axial 4width of index gear 34. .l v Index gear 34, as seen in Figures 7. and 8, comprises an ordinary gear having teeth-3|) conjugate to rack teeth 39 and .40. This results in the gear, and hence the work spindle .being accurately held againstrotation when teeth B9 are in full mesh with teeth 49, whichis the condition that exists during the cutting operation. Teeth 80 are also beveled as at 82, these bevels cooperating with bevels 90'and 9| on rack teeth 39 and 4D.

As seen in Figure 1, index gear 34 is mounted to reciprocate axially between rack teeth 39 and 40. Due to the bevels described, and the staggered relation of the `rack teeth, each complete reciprocation of the index gear advances the index gear one tooth space. Additionally, due to head 3| Yfor this purpose.

' The operation of my improved machine is obvious from the foregoing. Suitable tools, selected according to the nature of the work are rotated independently. Motorl5-reciprocates spindle 25, feeding the work into the tools to a definite predetermined but adjustable depth. Reciprocation of the spindle automatically indexes the work. After a work piece is completed, air cylinder 33 operates to push shafts 43, 4|, 53 to the left, releasing lock washer 55, which may be removed radiallyyand a new work piece substituted for the one completed.

While I have illustrated and described several specific embodiments of my invention, it will be apparent to those skilled in the art that various additions, modifications, omissions, combinations andsubstitutions may be made which will be within the spirit and scope of my invention as defined. by the appended claims.

What I claim as my invention is: l

l. A gear chamfering machine comprising a gear supporting spindle, a pair of cutter supporting spindles mounted at opposite sides of the axis of said first spindle, means for locking a gear on said rst spindle, means for reciprocating said rst spindle, and means effective on reciprocation of said spindle for indexing said spindle by the amount of the tooth spacing on said gear, said indexing means comprising a pair of spaced, fixed rack sections, and a gear carried by said flrst spindle and reciprocable between said rack sections, said rack sections and said last mentioned gear having cooperating inclined teeth portions for effecting indexing rotation of said first spindle.

2. In a gear chamfering machine having an indexable gear-supporting spindle and indexing means for indexing said spindle step by step: means, for locking a gear on said spindle in definite relation to said indexing means comprising -a bracket secured adjacent said spindle, a plunger slidable in said bracket toward and away from said spindle, said plunger having a tooth-engaging portion adapted to locate said gear on said spindie in definite relation as to rotation, clamping means for locking said gear to said spindle while retained in lsaid denite relation as to rotation thereon and resilient means biasing said plunger away from said spindle toward a position in which said tooth-engaging portion clears said gear.

3. In a. gear chamfering machine having an indexable gear-supporting spindle and indexing means for indexing said spindle step by step: means for locking a gear on said spindle in definiteV relation to said indexing means comprising a bracket secured adjacent said spindle, a plunger slidable in said bracket toward and away from sald spindle, said plunger having a tooth-engaging portion adapted to locate said gear on said spindle in definite relation as to rotation, clamping means for locking said gear to said spindle while retained in said definite relation as to rotation thereon, resilient means biasing said plunger away from said spindle toward a position in which said tooth-engaging portion clears said gear and lool;- ing means engageab-le with said plunger to retain the same in forward or gear-engaging position when desired. 4. In a gear chamfering machine having an indexable gear-supporting spindle and indexing means for indexing said spindle step by step: means for locking a gear on said spindle in defl- 

